## NEKG33 Mathematical methods for economists

## Chapter 4 : Day 04: Linear and quadratic functions

### By Lund University

Enough of algebra for now. Let's move on to analysis, specifically to linear and quadratic function. Remember the y=kx+m? That's the focus of today.

## Linear functions

This section is entirely focused on the most important class of functions, namely the linear functions. We will look at what we mean by the slope and the intercept of a linear function and we will look at how to determine the graph of a given linear function. We will also look at how to determine the equation of the function from, for example, two points on its graph.

#### Linear functions

#### Problem: Slope of a linear function

#### Problem: Graph of a linear function

#### Problem: Equations of linear functions from graphs

#### Problem: Equations of linear functions from two points or a point and a slope

#### Problem: System of equations and graphs of functions

#### Problem: System of equations with no solutions

#### Problem: Collections of points in the xy-plane

#### Problem: Collections of points in the xy-plane

#### Problem: Equations of a linear function from two points

#### Problem: Linear functions and the delta-notation

#### Problem: Equations of a linear function from a point and a slope

## Quadratic functions

In this section we will look at quadratic functions and polynomials and we study the graphs of these types of functions.